Automatic slitter scorers which include either a computer or miniprocessor have been proposed heretofore. See U.S. Pat. Nos. 3,651,723 and 4,010,677. Other prior art directed to automated slitter scorers include U.S. Pat. Nos. 3,961,547; 3,646,418; 3,831,502; and 3,587,374. In such slitter scorers, heads are moved along a shaft to a predetermined position and then are secured to the shaft for rotation therewith. It is known to simultaneously couple the shaft to all of the operative heads as per U.S. Pat. Nos. 3,951,024 and 4,006,671 instead of coupling each head individually to the shaft.
One problem with the prior art is inadvertent shifting of heads predisposed along a shaft due to vibration or the like prior to the heads being fixedly secured to the shaft. The problem is not solved by simultaneously expanding a portion of the shaft into locking engagement with the heads as taught by U.S. Pat. Nos. 3,951,024 and 4,006,671. Thus, the last two mentioned patents do not take into consideration inadvertent shifting of a head prior to the time when all heads are purportedly in their desired position and then simultaneously coupled to the shaft.
The present invention solves the above-mentioned problems of the prior art as well as other problems which will be made clear hereinafter.